In the past decade, video and audio magnetic tape have emerged as viable alternatives to traditional storage media such as silver halide film for recording, display and reproduction of images, sounds and video. Editing methods in the past originally stemmed from linear or sequential editing of film on a film device. Along with advances in storage media have come new methods of composition based on computerized digital editing techniques that have all but replaced manual editing of magnetic video and audio tape and related media. Digital composition software programs, such as those used to compose digital video, audio and related source materials, have found widespread application in multimedia presentation and authoring systems. Despite their power, these composition software programs require users to master complex interfaces, and adopt abstract representation models which are beyond the grasp of ordinary users.
For example, some prior art composition software programs include user interfaces that employ timeline-based, non-linear and non-spatial representations of what is inherently a temporal-based composition process making the composition software programs difficult to learn and use. The user interfaces are non-linear because various aspects of the composition are displayed as separate elements on different levels or layers. These composition software programs seek to mimic film based editing methods through the application of a timeline-based composition system and method.
However, unlike the film editor who has access to the visual scenes of a movie which he can cut and splice together to produce a desired sequence, the typical video editor has been forced to rely on computer software programs that simulate sequential frames of film on a timeline. The conventional non-linear digital editing method involves the use of computer software for displaying and manipulating a sequence of frames or images on a timeline typically with each frame individually displayed. Where multiple sequences are sought to be confined, each sequence is displayed on a separate, horizontal timeline. Audio to accompany the video is placed on a separate timeline. The video and/or audio sequences contained in each timeline are not viewable until a production stage is completed. While this method offers significant productivity gains over the complex and time-consuming task of manual editing, the timeline based method utilized in current non-linear digital video and audio composition systems is extremely complex, non-intuitive and cumbersome to use because of the multiple timelines or layers.
One of the problems with the prevailing non-linear composition method is that it breaks a composition into a non-temporal representation of multiple layers of image and/or audio sequences in what is inherently a temporal relationship. This method not only forces users to constantly switch between separate program modules to perform routine composition tasks for each layer, but greatly increases the complexity of the composition display due to the inherent need to accommodate multiple timelines or "layers", each with its own associated images. A user is forced to mentally visualize the combined layers as well as their effects as editing is performed. Thus the composition process is, as a consequence, very complex and tedious. As a result, much of the power of these composition software programs is untapped by all but the most advanced users due to the inherent complexity that results from attempting to represent a spatial and temporal composition process by means of non-spatial, timeline-based models and methods.
U.S. Pat. No. 4,538,188 to Barker et. al. discloses a video composition method and apparatus utilizing non-linear timeline based composition. Each layer of the video composition method is presented as numerous individual images in a time sequence or timeline order. There are many inherent difficulties and inefficiencies associated with the prior art method that results from the display of temporal source materials in a non-temporal or timeline fashion.
However, despite its inherent limitations, the use of digital non-linear editing methods has increased significantly in recent years due to associated cost advantages offered over traditional video editing methods. Unfortunately, this departure from traditional video editing techniques has in some respects dampened the creative talents of modem video and audio directors who are no longer able to apply their skills directly to the composition process and must instead rely upon intermediate personnel to manipulate the image and audio sequences scattered across multiple timeline layers. Using the non-linear method of digital-based composition, the director's feel for the composition process is greatly diminished. One advantage of composing with the traditional physical editing method using silver halide film, is the ability to react quickly to the temporal nature of the media. Thus, a given sequence of film can be run back and forth, viewed repeatedly, edited and quickly "spliced" together with other sequences to form a completed segment. Thus the source material is treated as an entire object, one that can be combined with other objects to create a composition sequence. The ability to achieve this same effect in a digital non-linear editing environment is highly desirable.
It is therefore an object of the present invention to provide a novel non-timeline, non-linear digital multimedia method and system.